[Code of Federal Regulations] [Title 49, Volume 3] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR193.2009] [Page 127] TITLE 49--TRANSPORTATION CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PART 193_LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS-- Table of Contents Subpart A_General Sec. 193.2009 Rules of regulatory construction. (a) As used in this part: (1) Includes means including but not limited to; (2) May means is permitted to or is authorized to; (3) May not means is not permitted to or is not authorized to; and (4) Shall or must is used in the mandatory and imperative sense. (b) In this part: (1) Words importing the singular include the plural; and (2) Words importing the plural include the singular.